Fat-washing is a technique pioneered in New York City and was popularised due to Don Lee's Benton Old Fashioned cocktail made with bacon fat-washed bourbon.

How to make bacon fat-washed bourbon:

1. Grill 24 slices of smoky bacon to obtain at least 60ml (2oz) of well-rendered warm bacon fat.
   
2. Pour this into 70cl bourbon in a wide-mouth sealable jar.
   
3. Leave to infuse at room temperature for a few hours and ideally a day, shaking occasionally.
   
4. Stand the jar in a freezer to solidify the fat.
   
5. After a few hours in the freezer, the frozen fat will form a layer on top of the bourbon.
   
6. Then, clarify the bourbon by pouring through a coffee filter or Superbag into a clean bottle.